When this show first premiered in 2010, the character of Kono Kalakaua (played by Grace Park) was written to be a rookie cop in her mid-20's. Park was actually 36 years old when the show premiered. Her character is supposed to be younger than commanding officer Steve McGarrett (played by Alex O'Loughlin). In real-life, Grace Park is two years older than Alex O'Loughlin.

During the opening credits the camera zooms in on McGarrett (Alex O'Loughlin) standing on a balcony. It is the same balcony on the same building that McGarrett (Jack Lord) is standing on during the opening credits of the Hawaii Five-O (1968).

During season two of the updated series, McGarrett's Chevrolet Silverado Crew Cab truck is shown with license plate number "F6-3958," a nod to the original series, where Jack Lord's McGarrett had this plate number for his personal state issued car, used for both the 1968 Park Lane and 1974 Marquis Brougham.

In the original series, Five-0's offices were purported to be on the second floor of the I'olani Palace, which in the late 60's to early 70's was in fact a state office building, but has since been restored as a royal residence museum. Five-0's offices for this series are depicted as being in Alii'olani Hale (right across the street), a state office building of similar architecture built in the 1870's which actually houses Hawaii's Supreme Court.

James MacArthur who originated the role of Danny "Danno" Williams in the show's original incarnation was scheduled to make a guest appearance during the first season. Unfortunately, he died before he was able to make an appearance.

When CBS announced this series for the fall of 2010, they released the opening credits from the pilot online. They featured an electric guitar version of the classic theme, and it was met with positive results. Producers revealed they hadn't decided whether or not to use it on a permanent basis, so they decided to stay with the classic. They brought in a full orchestra to re-record it, and three of the members had even played on the original. The electric guitar rendition of the Hawaii Five-O theme song was later used on promotional advertisements.

Dennis Chun, the son of the original Chin Ho Kelly, Kam Fong, has a recurring role as HPD Sgt. Duke Lukela. The role of Duke is also a tribute or reference to actor Herman Wedemeyer, who played Duke in the original series. Dennis Chun also had roles in the original series, as three different, unrelated characters, in three different episodes, one during the 1973-1974 season, and two during the 1974-1975 season.

In the updated series, Danny Williams got his nickname from his daughter Grace, who called him "Danno" because she could not pronounce "Daniel" (or Daddy, by inference) when she was learning to speak. In the original series, no reason was specifically given for why Danny's nickname was Danno, and Danno did not have a daughter.

The title of the original series, Hawaii Five-O (1968), and that of the updated series, Hawaii Five-0 (2010), are pronounced the same: "Hawaii Five-Oh". However, they are spelled differently. The former uses the capital letter "O" as a pronunciation spelling for the number zero. The latter uses the numeral "0" instead.

Grace Park plays Kono, a role originally played by Zulu. This marks the second time Park has starred in a re-imagined television series playing a role originated by a man, the first being Boomer from the rebooted Battlestar Galactica (2004) series, a role played in the original by Herbert Jefferson Jr..

CBS wanted to bring the series back one year sooner for the 2009-2010 season, with Edward Allen Bernero in charge of production. The plot would have been a sequel with Steve McGarrett Jr. taking over the unit from Steve McGarrett Sr. It didn't go beyond the scripting stage. In 2009, Alex Kurtzman and Roberto Orci took over and decided to reboot the series instead of make it a sequel to the original.

In the updated series, Steve's middle name is Jack in honor of Jack Lord, who played Steve McGarrett on the original series, while in the original series, Steve's middle name was "Aloysius" (pronounced AL-oh-wish-uss).

The wife of the original series creator, Leonard Freeman (who died in 1974, age 53), was actress Joan Taylor (known after her marriage by her given first name, Rose, along with her husband's family name, Freeman, making her Rose Freeman), died on March 4, 2012. After her death, she was the dedicatee "In Loving Memory Of Rose Freeman" on the March 19, 2012 broadcast of Hawaii Five-0 (2010).

What seems like a mistake regarding the ranks of the team is actually a nod to McGarretts military service with the Navy S.E.A.L.s. In the SEALs and other special forces units rank is not as important as experience and expertise so a lower ranking member could be team leader. In cases where the highest ranking member is team leader the rest of the team is usually free to make suggestions and plans, acting almost as a pseudo democracy with the team leader making the final call as to what they do. A good example of this is a film is Lone Survivor (2013) starring Mark Wahlberg and Taylor Kitsch, during the scene in which the team argues over what to do with the goat herders who discover them and American Sniper (2014) when Chris Kyle asks to start his own task force and when he joins the Marines for house clearing despite his assignment being to provide cover fire as a sniper.

During the opening credits (Seasons 1 to 6), the Hawaiian Airlines jetliner seen is an Airbus A330-200. Hawaiian Airlines signed a $4.4 billion Memorandum of Agreement with Airbus in 2007 where the A330s have been used in place of their existing Boeing 767s for nonstop flights to the U.S. East Coast. The 767s in service will be retired after 2015.

Chin Ho was originally dismissed from the Honolulu Police Department after being falsely accused of taking bribes. Steve chose him for the task force because he didn't believe the accusations, and because Chin Ho was his father's former partner. It is later revealed in the latter half of Season 1 that Chin's uncle was the one who was involved (to pay off medical bills where Chin became a fall guy who took the blame where he was protecting his extended family) which resulted in his reinstatement to HPD as a lieutenant.

Leonard Freeman, the producer of the original Hawaii Five-O (1968) series, named the Wo Fat character after a now-defunct restaurant in Honolulu Chinatown. The Wo Fat building remains on the National Register of Historic Places.

Richard T. Jones, as the second governor, Sam Denning, succeeded Jean Smart, the first governor, Pat Jameson. Both roles are a reference or tribute to the role of Governor Paul Jameson, and the actor who played him for the entire run of the original series, Richard Denning.

Danny's favorite team is the New York Jets and when he moved to Hawaii he adopted the University of Hawaii's football team as his favorite college team due to the similar color scheme to the Jets' uniforms.

The car the group is seen driving around in is a 2010/2011 Camaro LT with a V6 engine, the RS performance package, and police lights added to the front end. McGarrett is seen numerous times driving the Camaro although it's Danno's car. GM's Chevrolet division is the motor vehicle provider. In the original Hawaii Five-O (1968), Ford Motor Company was the motor vehicle provider, with both Ford division and Mercury division vehicles being used by Five-O personnel. However, the lead vehicle was always Jack Lord McGarrett's Mercury. For most of the first seven seasons of the original show, Steve's car was a black on black (sometimes referred to as "triple black") 1968 Mercury Parklane Brougham 4-door. The Park Lane was last used during the 11th season of the original series where it sat in a warehouse for several years - the Park Lane sedan used in the early seasons was restored and now in the hands of a Chicago, Illinois resident. After Season 8, McGarrett drives a 1974 Mercury Marquis Brougham hardtop sedan, and after the original series ended its run in 1980, Jack Lord gave the Marquis to his stunt double, John Boley Nordlum. In Hawaii Five-0 (2010) that same car make, model, and color 1974 Mercury is shown being stored in the garage of Steve's house, and Steve explains to Danno that his father had been restoring the old Mercury before he was kidnapped. This is a tribute to the very famous car McGarrett used in the later seasons of the original series.

The HPD lab technician Charlie Fong introduced late in Season One is based on the character Che Fong in the original series. This also holds true with Lori Weston (introduced in Season Two) - named similarly to Sharon Farrell's character (Lori Wilson) during the 12th Season of the original Hawaii Five-O, and Max Bergman (introduced in Season One, recurring in Season Two, but with on screen credit for every episode in Season Two of the updated series), who was based on the character of Doc Bergman, as played by Al Eben in the original series, although he was sometimes simply credited as either "Doc" or "Coroner" in 51 episodes, beginning with the fourth season, and he also portrayed three other characters before the fourth season, two of those were also a doctor.

The character of Wo Fat, the principal arch-villain of both the 1968 original (as portrayed by Khigh Dhiegh) and 2010 rebooted series (as portrayed by Mark Dacascos), appeared just eleven times (in thirteen episodes, as some were two-parters) in the 1968 original series, over the course of twelve years/279 episodes, including the pilot (or first episode) of the original series, and the last episode in 1980, entitled "Woe to Wo Fat." In the 2010 reboot, Wo Fat was also introduced in the pilot (or first episode), but has already appeared in nine episodes, up to and including the third season premiere. To put this in perspective, in the original series, Wo Fat appeared in thirteen episodes out of 279, or approximately one out of every 21.5 episodes, but in the 2010 reboot, Wo Fat has appeared in nine out of forty-eight episodes (through season three premiere), or approximately one out of every 5.33 episodes, much more frequently than in the original. Both incarnations average between twenty-three and twenty-four episodes per season.

General Motors provided the motor vehicles for the series during the first 4 seasons - beginning in Season 5 the contract with GM was canceled since two of the leading roles (Chin Ho and McGarrett) drove vintage Ford vehicles (Chin with a 1966 Mustang coupe and McGarrett with a 1974 Mercury Marquis Brougham). This also affected the Honolulu P.D. squads used throughout the series - the Impala 9C1 after the 2013 model year (based on the previous 1996-2013 model sold as the Impala Limited, which is scheduled to be phased out in 2016) is only sold to fleets or rental car agencies. Also, the 2011-present Chevrolet Caprice PPV (which is the replacement for the Impala 9C1) is not sold to the general public - hence the production crew using the Impala for the squads.

William Sadler, who portrays Steve's father, John McGarrett, and Christine Lahti, who portrays Steve's mother, Doris McGarrett, were both born in April 1950, Sadler on April 13, 1950, and Lahti on April 4, 1950, just nine days apart.

In season 3, episode 15 called "Hookman" they pay homage to the 1987 movie "Robocop" played by Peter Weller who is the special guest star of the show. In the gun store scene, on the wall is the same modified Beretta Machine Pistol Robocop shoots.

In the episode Hawaii Five-0: Ho'oma'ike (2014) Kamekona's last name is revealed to be Tupuola. It appears in a school year book that the own Kamekona is watching to help Chin Ho Kelly in an old murder investigation happened when Kamekona was student.

Several references to the Star Trek franchise (from the original series, spinoffs, and feature films with the original series and spinoff cast including the reboot) have been featured throughout the series - during Season 2 Dr. Bergman's VW 181 has a Warp 9 personalized license plate, while in Season Three George Takei guest starred as Chin's uncle (Takei appeared during the classic Five O back in 1975 during Season 8). Also Dr. Bergman's feud with Dr. Dhawan was over a Yeoman Janice Rand action figure which was revealed during Season 5. Supporting cast member Terry O'Quinn (Joe White) did appear on a Star Trek spinoff as a Starfleet admiral, and during Season 7, Rosalind Chao (Keiko Ishakawa O'Brien from DS9 and TNG) as the Governor of Hawaii. Main cast member Daniel Dae Kim did appear on Star Trek Voyager and Enterprise, and writers Roberto Orci and producer Alex Kurtzman (who are part of the Kelvin timeline Star Trek film series). Also, Peter Weller (who guest starred in Star Trek: Enterprise and Into Darkness as Adm. Alexander Marcus) has directed some of the series including the one which he directed (Hookman).